Fluid-compressor.



No. 728,955. I PATENTED MAY 26, 1903 v I G. V. MITCHELL.

FLUID COMPRESSOR.

APPLICATION IILED DEO. 2, 1901.

N0 MODEL.

2 SEEETB-BHEET 1.

No. 728,955. PATENTED MAY26, 1903..

G- V. MITCHELL. FLUID COMPRESSOR.

APPLICATION rum) DBO. 2, 1901.

no Mann. 2 BEETS-SHEET 2.

llimmnillli I UNITED STATES Patented May 26, 1903.

GARRY V. MITCHELL, OF ELMIRA, NEW YORK.

FLUID-COMPRESSOR.

SPECIFICATION forming part of Letters Patent No. 728,955,0latd May 26, 1903.

Application filed December 2,1901. Serial No. 84,398. (No model.)

tion of the main inlet-valve is controlled by the predetermined limit of pressure of the fluid within the receiver or distributing-pipes.

One object of my invention is to provide means to close the fluid-passage to the compression-chamber when the pressure of fluid within the compression-chamber overruns or exceeds the predetermined limit of pressure of the fluid within the receiver or distributing-pipes and by such action avoid all the noise of escaping fluid from the' ordinary unloading-valve and at the same time relieve the motive power from unnecessary work of compressing more of the fluid than is needed and allowing it to escape from the common unloading-valve.

Another object of my invention is to so construct the main inlet valve for fluid compressors that the same will be automatically operated for the admission of fluid and then closed to retain the same while the operation of compression is being effected.

Another object of my invention is to provide means to so control the main inlet-valve by the maximum pressure in the receiver or.

distributing-pipes that the exterior fluid-supply cannot enter the compression-chamber at certain times duringthe movement of the piston when the receiver or distributing-pipes are charged with fluid.

My invention consists in the novel features of construction hereinafter described and claimed.

In order that my invent-ion may be fully understood, I will proceed to describe it in detail with reference to the accompanying drawings, in which- Figure l is a side elevation of myimproved fluid-com pressor,which is adapted to be driven by a belt. Fig. 2 is a detail view, partly in section, of the means for controlling the operation of the main inlet-valve by excess of pressure within the receiver or distributing pipes. Fig. 3 is adetail longitudinal section of thetelescopingorextensible pitman. Fig. 4is adetail perspective view of the bell-crank lever, which is fixed to the stem of the main inlet-valve. Fig. 5 is a detail perspective view of the upper end of the pitman. Fig. 5 is a detail vertical section of the samein a plane of the axis of its pivot. Fig. 6 is a vertical section of the compression cylinder, taken on the line 6 6 of Fig. 7. Fig. 7 is a top plan view of the compression cylinder. Fig. 8 is a horizontal section of the compression-cylinder, taken on the line 8 8 of Fig. 6. Fig. 9 is a detail transverse section of the main inlet-valve, taken on the line 9 10 of Fig. 8, showing the main inlet-valve in fullyopen position. Fig. lOisasimilar viewshowing the main inlet-valve in its extreme closed position. Figs. 11, 12, and 13 are detailfront views of the bell-crank lever on the stem of the main inlet-valve and the upper end of the pitman, whereby the lever is moved to operate the main inlet-valve and showing the travel of .the parts from the fully-open to the extreme closed positions of the main inletvalve.

lis the base frame or standard, upon which is supported a cylinder 2, having a compression-chamber 2 and a surrounding waterjacket 2 Journaled in the base-frame 1 is a drivingshaft 3, upon which is secured between suitable bearings a driving-pulley4. Constituting part of the shaft is a crank 5, to which is connected the lower end of a piston-rod 6. The upper end of the piston-rod 6 is connected to a piston 7, and by these means a reciprocating motion is imparted to the piston 7 within the compression-chamber 2.

It will be readily understood that the compressing device is single-actingthat is, the fluid is admitted and discharged at one end only; but my invention is equally applicable to a double-acting machine where the fluid is received into and discharged from both ends of the compressing-cylinder. I

8 is the hollow head of the com pression-cylinder, in which is located one or more discharge-valves 9 and having a suitable waterchamber 8 on one side thereof in close proximity thereto and in communication with the water-jacket 2 which surrounds the compression-chamber and through which water is freely circulated, entering at an opening 30 at one end of the cylinder and out through an opening 31 at the other end of the cylinder to reduce the temperature of the cylinder, and consequently the outgoing fluid and the operating parts.

10 is a discharge-opening in the cylinderhead 8 for the fluid acted upon and is controlled by a valve 9. The discharge-opening has a suitable pipe connection 10 to the point of distribution or to a receiver. (Not shown.)

11 is a fluid-supply opening communicating with an inlet-chamber 8 in the cylinderhead 8. The water-chamber 8' in the cylinder-head is separated from the valve 9 by a valve-casing 9, closed bya screw-cap 9 while the water and inlet-chambers are separated by a partition 8 and a valve-housing 8 eX- tending across and merged into the compression-cylinder, in which is located a cylindrical rocking or oscillating main inlet-valve 12, adapted to oscillate in hearings in terminals 8 at the ends of the valve-housing 8, one of the terminals being closed by a cap 8 secured by bolts 8 and the other terminal having a stem-sleeve 13, fitted thereto and secured by bolts 13 The outer end of the main inlet-valve is formed with a transverse slot 12 in which fits the T-head 13 of a valvestem 13, journaled in the stem -sleeve 13. The main inlet-valve 12 is formed with a suitable passage or passages to provide communication between the inlet-chamber 8 and the compression-chamber 2'. 14 represents longitudinal slots for this purpose formed in the upper part of the main inlet-valve, While the lower part is cut away to provide a recess 12 and a fiat side to the main inlet-valve flush with the inner end of the compression-chamber when the main inlet-valve is closed, as shown in Fig. 6. The slots 14 in the closed position of the main inlet-valve (shown in Fig. 6) are slightly inclined downwardly toward the outlet thereof. By forming the inclined slots 11 and the recess 12 in the main inlet-valve a wedge-shaped web or partition 14 is produced, and to enable the fluid to pass into the compression-chain ber, both over and beneath this web or partition, when the main inlet-valve is fully opened I provide a longitudinal cavity 12 in the lower edge of the web or partition at the inlet side of the main inletvalve, through which communication is also opened up between the inletchamber in the head and the compressionchamber in the cylinder to enable the latter to be filled more quickly than when only the upper passage is opened.

I will now describe the means for operating the main inlet-valve.

15 is the upper arm of a bell-crank lever formed with a lower bifurcated arm 15 and fixed to the end of the valve-steml3, so as to operate the main inlet-valve from an eXten sible pitman 16, connecting the upper arm of the bell-crank lever with a stud or bolt 17' on the crank-wheel 17 of the driving-shaft 3. The construction of this pitman 16 is such as to be extensible, and thus permit of the main inlet-valve remaining stationaryduring a portion of the travel of the piston.

16 is the tubular lower section of the pitman journaled to a stud or bolt 17 on the crank-wheel 17, and 16 is a tubular upper section having a shouldered lower end 16 seated on and screw-threaded into the upper end of the lower section 16' and formed with a lug 16 at its upper end. Adapted to slide in these tubular sections of the pitman is a rod 18, having a bifurcated head 18' journaled to the upper arm 15 of the bell-crank lever by means of a pivot-pin 19, having an inner extension or tooth 19.

20 is a coil-spring located Within the lower section 16, surrounding the lower part of the rod 18 within the lower sect-ion 16 of the pitman. The lower end of the rod 18 is pro- Vided with a screw-threaded extremity 18 on which are located a nut 20 and'a jam-nut 20, between which and the shoulder 21 on the lower end 16 of the upper section 16 the spring is confined, and the tension thereof can be adjusted to overcome the frictional resistance to the movement of the main inletvalve 12 by raising or lowering the nut 20 and securing it by the jam-nut 20. The spring 20 has a tendency to pull the rod 18 inwardly and to press the head 18 of the same downwardly against the lugs 1b of the upper section 16 of the tubular part to hold the parts of the pitman 16 in normal position.

18 is a cushioning-washer located around the rod 18 between the head 18 thereof and the lugs 16 of the upper section 16 In order to arrest the movement of the main inlet-valve .12 and the downward movement of the upper end of the pitman temporarily to avoid the overloading of the receiver or distributing-pipes, while permitting the crank-wheel 17, with the lower end of the pitman, to continue to operate, I provide a detent 22, secured to one side of the compression-cylinder, which I will now describe.

22 is a bracket secured in position by bolts 22 and formed with a oupshaped fluid-chamher 22 in which is seated a diaphragm 23, secured thereto by a ring 22 fastened by screws 2 1is a pipe which is connected with the chamber beneath the diaphragm and with the receiver or fluid-distributing pipes.

The ring 22 is formed on its outer edge with bearing-lugs 26 for the journal-pin 27 of a bell-cran k lever having an upwardlyextending long arm 28, adapted to contact with the extension or tooth 19 at stated times, and with a laterally-extending short arm 28, supported upon a push-pin 29, secured to the diaphragm by a collar 30, through which the push-pifn 29 extends. The ring 22 is formed 3 amount of resistance.

on its inner side with a bridge 25,u nder which the free end of the short arm 28 extends for receiving a loading device, whereby it is held down on the push-pin 29 with the desired This loading device consists in the presentinstance of a coil-spring 31, surrounding an adjustable screw 32,working through the bridge 25 and provided with a jam-nut 33.

By the construction of the bell-crank lever secured to the valve-stem 13 of the main inlet-valve 12 and the pitman ]6 connection to the crank-wheel 17 on the driving-shaft 3, a positive movement is imparted to the main inlet-valve from the position shown in Fig. 13 to the position shown in Fig. 12 by the following means: The rod 18 of the pitman 16 being connected to the upper arm of the bellcrank lever and the lugs 16 of the upper section 16 of the tubular part being located above the lower arm 15' of the bell-crank lever, the lugs 16 will engage or contact with the upper surface of the lower arm 15 and intermittently operate the bellcrank lever upon the downward movement of the pitman until the position shown in Fig. 12 is reached, when the bell-crank lever will be released from contact or engagement with the lugs 16, and the bell-crank lever will continue its travel to the position shown in Fig. 11 under tension of the spring within the pitman or will be retained in the position shown in Fig. 12 by the detent. The return movement of the bellcrank lever from the position shown in Fig. 11 to that shown in Fig. 13 is positive through the full travel.

I will now describe the operation of my device. A downward movement being imparted to the piston 7 with the main inlet-valve 12 in the position shown in Fig. (3 the main inletvalve will move in unison with the piston to the position shown in Fig. 9. Fluid will enter from the inlet-chamber b to the compressionchamber 2 through the passages l-l and also through the cavity 12 beneath the valve, as indicated by the arrows, the piston 7 and the main inlet-valve 12 always moving in unison so long as the pressure in the receiver or the distributing-pipes remains below the maximum pressure. inlet-valve through a complete cycle of operation will be to the position for charging the compression-chamber shown in Fig. 9 from the position shown in Fig. (5, thence back to the position shown in Fig. 6, when the compression-chamber will be full of fluid and the main inlet-valve will be closed to the exterior. Du ring compression of the contents of the compression-chamber there will be a movement of the main inlet-valve from the position shown in Fig. 0 to the position shown in Fig. 10, thence back to the position shown in Fig. 6, and during the last movement the dis charge-valve 9 will have opened and permitted the discharge of compressed fluid to the receiver or distributing-pipes, such operations taking place until the desired pressure The movement of the main in the receiver or distributing-pipes will have been attained,after which any excessive pressure will cause the detent and pitman connection to perform their intended operation which is as follows: The excessive pressure within the cup-shaped chamber 22 on the under side of the diaphragm 23 will cause the push-pin 29 of the latter to be pressed outward against the short arm 28 of the bellcrank lever andthe loading device 31 carried thereby, thus causing the upper end of the long arm 28 of the bell-crank lever to pass beneath and engage the extension 19' of the pivot-pin 19, preventing any further movement of the bell-crank lever or main inletvalve with which the latter is connected to open, thus locking the pitman-rod 18 and bringing the spring within the pitman 16 under greater strain than normal and causing the tubular portion of the pitman to slide downwardly on the pitman-rod and the pit- .man to continue its travel at its lower end through the rotation of the crank-wheel17 until such time as the tubular portion and the pitman-rod abut at their upper ends, when the main inlet-valve will move from the position shown in Fig. 6 to the position shown in Fig. 10, and thence back to the position shown in Fig. 6, and there remain until the crank-wheel 17 shall have completed its rotation. The long arm 28 of the detent bellcrank lever remains in position to contact with the extension 19 of the pivot-pin 19 until the pressure beneath the diaphragm shall have fallen below the maximum pressure in the receiver or distributing-pipes, when the long arm 28 of the detent bell-crank lever will be moved out of the path of the extension 19' of the pivot-pin 19, and the main inlet-valve permitted to receive its full travel from the position shown in Fig. 6 to the position shown in Fig. 9. This movement continues until the long arm 28 of the detent bellcrank lever has again engaged the extension 19 on the pivot-pin 19.

Other means may be employed to impart movement to the piston than that shown without departing from the object described.

Having thus described my invention, the following is whatl claim as new therein and desire to secure by Letters Patent:

1. A fluid-compressor comprising a cylin der having a compression-chamber, a cylinder-head having a fluid'inlet chamber and a valve-housing extending across the cylinderhead, a piston within the compression-chamber, a cylindrical rocking or oscillating, main inlet-valve having a lever-arm and mounted in the valve-housing, an extensible pitman connected with the lever-armof the main inlet-valve, means for operating the piston and pitman in unison, and a detent device associated with the cylinder and adapted to be controlled by the fluid under pressure in the receiver, or distributing-pipes, and to arrest the movement of the main inlet-valve and keep it closed without stopping the movement of the pitman, while the predetermined pressure in the receiver, or distributing-pipes 1s exceeded.

2; A fluid-compressor comprising a cylin der having a compression-chamber, a cylinder-head having a fluid-inlet chamber and a valve-housing extending across the cylinderhead, a piston within the compression-chamber, a cylindrical rocking or oscillating main inlet-valve having a recess to receive the piston and a lever-arm, and mounted in the valve-housing, an extensible pitman connected with the arm of the main inlet-valve, means for operating the piston and pitman and a detent device adapted to be controlled by the fluid under pressure in the receiver, or distributing-pipes, and to arrest the movement of the main inlet-. valve and keep it closed Without stopping the movement of the pitman, while the predetermined pressure in the receiver or distributing-pipes is exceeded.

3. A fluid-compressor comprising a cylinder having a compression-chamber, a piston within the compression-chamber, a main inlet-valve for controlling the flow of fluid into the compression-chamber, a lever-arm whereby the main inlet-valve is controlled, an extensible pitman for operating the main inletvalve, a pivot-pin having an extension and connecting the pitman with the lever-arm means for operating the piston and pitman in unison and a detent device having an arm adapted to engage the extension of the pivotpin and to be controlled by the fluid-pressure in the receiver or distributing-pipes and to arrest the movement of the main inlet-valve and keep it closed Without stopping the movement of the pitman while the predetermined pressure in the receiver or distributing-pipes is exceeded.

4. A fluid-compressor comprising a cylinder having a compression-chamber, a cylinder-head having a fluid-inlet chamber and a valve-housing extending across the cylinderhead, a piston within the compression-chamber, a cylindrical rocking or oscillating main inlet-valve having a lever-arm and mounted in the valve-housing, an extensible pitman consisting of a tubular portion formed with lugs and a shoulder and a rod connected with the lever-arm, extendinginto the tubular portion, and having a head, a spring surrounding the rod between the shoulder and the head, means for operating the piston and pitman in unison, and a detent device adapted to be controlled by the fluid under pressure in the receiver or distributing-pipes and to arrest the movement of the main inlet-valve and keep it closed without stopping the movement of the pitman while the predetermined pressure in the receiver or distributing-pipes is exceeded.

5. A fluid-compressor comprising a cylinder having a compression-chamber, a piston within the compression-chamber, a main inlet-valve for controlling the flow of fluid into the compression-chamber, an extensible pit-- man, for operating the main inlet-valve consisting of a tubular lower section, a tubular upper section having lugs at its upper end, and shouldered on, and screw-threaded to, the lower section, a rod having a head at its upper end and its lower end screw-threaded and adapted to slide in the lower section, nuts adjustable on the screw-threaded end and a coil-spring surrounding the rod between the lower end of the upper section and the nuts, means for operating the piston and pitman in unison, and a detent device adapted to be controlled by the fluid under pressure in the receiver or distributing-pipes and to arrest the movement of the main inletvalve and keep it closed without stopping the movement of the pitman while the predetermined pressure in the receiver or distributingpipes is exceeded.

6. A fluid-compressor comprising a cy1in-' der having a compression-chamber, a piston within the compression-cylinder, a main in let-valve for controlling the flow of fluid into the compression-chamber, a bell-crank lever, whereby the main inlet-valve is controlled, having an upper arm and a bifurcated lower arm, an extensible pitman, for operating the main inlet-valve, consisting of a tubular portion having lugs, beneath which the bifurcated lower arm is adapted to extend and a rod, adapted to slide within the tubular portion, having a head-spring seated against the tubular portion, a pivot-pin having an extension and connecting the head of the rod with the upper arm, means for operating the piston and pitman in unison and a detent device having an arm adapted to engage the extension of the pivot-pin and to be controlled by the fluid-pressure in the receiver or distributing-pipes and to arrest the movement of the main inlet-valve and keep it closed without stopping the movement of the pitman while the predetermined pressnre in the receiver or distributing-pipes is exceeded.

7. A fluid-compressor comprising a cylinderhaving a compression-chamber, a main inlet-valve for controlling the flow of fluid into the compression-chamber, and a detent device consisting of a bracket having a fluidchamber and a pipe leading thereto from the receiver or distributing-pipes, a diaphragm, mounted on the fluid-chamber,having a pushpin, a ring having journal-bearings and a bridge, a bell-crank lever mounted in the journal-bearings, having a long arm adapted to arrest the movement of the main inlet- .valve and keep it closed, and a short arm GARRY V. MITCHELL.

Witnesses:

JAMES COOPER, W. WOOLSEY. 

